Photosensitive compositions (radically polymerizable compositions) are obtained by adding a photopolymerization initiator to a polymerizable compound having an ethylenically unsaturated bond. The photosensitive compositions can be polymerized and cured by being irradiated with an energy beam (light) and are thus used in photosensitive printing plates, various photoresists, and the like.
With regard to a photopolymerization initiator to be used in the photosensitive compositions (radically polymerizable compositions), Patent Literature 1 discloses an optical fiber using an α-aminoalkylphenone derivative as the photopolymerization initiator, Patent Literature 2 discloses a photopolymerizable composition using an α-aminoalkylphenone derivative as the photopolymerization initiator, and Patent Literature 3 discloses a novel α-aminoacetophenone photoinitiator.
However, the α-aminoalkylphenone derivatives described in Patent Literatures 1 to 3 have insufficiently low sublimability and thus cause the contamination of a photomask and a heating furnace with sublimates, and the like.